The girl, whose name has not been released, fell on the Carnival Glory cruise ship while it was docked at the Dante B. Fascell Port of Miami on Saturday morning. Miami Fire Rescue personnel responded to the scene around 8:15 a.m. ET and provided emergency care to the child, according to the Miami-Dade Police Department.
The girl was subsequently taken to the nearby Ryder Trauma Center, where she died from her injuries, police said.
Erika Benitez of Miami-Dade Fire Rescue told ABC News the girl was in critical condition when she arrived at the hospital.
It's unclear what led the child to fall. Homicide detectives are investigating the incident, police said.